This application relates to transparent electronics.
Transparent electronics can be implemented in various applications, including displays,2-5 solar cells,6,7 charge-coupled devices (CCDS),8 and UV detectors.9,10 The core technology to realize the transparent electronics requires the development of high-performance transparent thin film transistors (TTFTs), with high device mobilities, moderate carrier concentrations, low threshold voltages, and steep subthreshold slopes.11 Currently, TTFTs fabricated with amorphous or polycrystalline transparent conducting oxide (TCO) thin films have been widely studied, including ZnO, SnO2, CuAl02 and many other semiconductor oxides.1,12-16 However, TTFTs made from these materials usually exhibit rather low mobilities (0.2-120 cm2V−1 sec−1) and high threshold voltages (Vth: 10-20 V).14-17 For instance, TTFTs with amorphous indium gallium oxide (α-IGO) films display device mobility of 7 cm2V−1 sec−1, a current on-off ratio of 104, and an inverter gain of 1.5 on glass substrates.18 These results clearly indicate that the performance of TCO thin film-based TTFTs may limit their operation in high frequency applications and has significant room for further improvement.